Just going to add my 2cents because I withdrawaled from methadone and it was absolutely traumatizing. If you go to a posh hospital (I worked in one) they gave patients blind detox dosages via IV. We used morphine IR twice a day for 9 days, tapering began pretty much immediately and it worked successfully. We used dilaudid for alcohol withdrawal though. I say yes, yes you can use it to ease the pain. However, without someone controlling it and depending on the amount you're taking and how long or when you began it (remember that real withdrawal from methadone takes 72 hours from the last dose), you could get yourself into an entire new habit.
My suggestion, having been through it and also as a nurse:
Blood pressure meds - NOW or those rsl will drive you insane.
valium or xanax... you need it for at least 3-6 months. It takes about 6 months to feel human or get more than 4 hours of sleep. You need sleep help and anxiety too for a bit.
If you're able to get loratabs or something lower on that opiate spectrum, I suggest that because dillies are pretty fucking strong (like old opana or fent). Coming off of hydrocodone is much easier than dilaudid